Over the last 20 years, the Love Me Tender animal rescue in central Tennessee has rounded up more than 1,000 abandoned dogs. And although most are timid and untrusting, CBS News correspondent Steve Hartman reports, one Rottweiler named Ella was notably different.

"I could just tell right away she was somebody's baby. She just didn't act like a stray dog to me," said Kathy Wilkes-Myers, who found the dog a few months ago.

Ella was emaciated and drinking from a drainage ditch along an empty stretch of highway. Kathy says it's typical for people to dump unwanted pets in the middle of nowhere - but again, the dog's demeanor convinced her there was more to the story. So she did some detective work, and what she found is a heart-wrenching tale of unending loyalty.

"She was hoping her family could come back. But they couldn't. They couldn't come back. It just breaks your heart," said Kathy.

Kathy found the first clues to this mystery - broken glass and tail lights - right near where she found the dog.

And just down from there, she found a second set of even more intriguing clues: personal items gathered up. By the dog, she assumed.

"It was like she was sleeping with them - or waiting with them," Kathy said.

She took a picture with her cell phone and then gathered the items. They were mostly random, personal things - toothbrush, comb, razor, a candle that said Michelle, but nothing that would explain anything - although now, she did have a hunch.

Kathy remembered two weeks earlier she'd driven by an accident on the same stretch of highway. She remembered because it was such a horrible crash. A single car had flipped over and landed on the side of the road, at just about the same spot where she found the dog.

Based on what she saw that day, Kathy figured there was no way a person could have survived, but what about a dog? So she called the highway patrol.

"She gave me the mom's name and the dad's name and the mom's name was Michelle. And I thought, 'Oh my God, this is their dog," she said.

Thrown from the car, rescue crews never saw the dog. She spent 13 days scavenging for food along the highway - and 13 nights bedding down with whatever she could find that smelled like her lost family.

"That's the last spot she saw her family and she was going to stay there," Kathy said.

Kathy figured it all out. But fortunately, she got one thing very wrong. Someone did survive the crash. In face, all five family members survived.

"I'm lucky to be sitting here with my family," said Joe Kelly, the family's father.

After two weeks believing that their dog, Ella, had died, the family of Joe and Michelle Kelly got the most wonderful, slobbery surprise of their lives.

For the first time since the accident, the Kelly's had a good reason to cry -all thanks to a dog who refused to forget her family - and the stranger who refused to take lost for answer.

Unfortunately, it was a bittersweet reunion because of the accident and the medical expenses, the Kelly family has had to temporarily relocate to a place that doesn't allow dogs.

The good news is, Kathy has promised to hold onto Ella for as long as the Kelleys need to get back on their feet.